Archive-Team
/
zfs
2
0
Fork 0
Code Issues Pull Requests Packages Projects Releases 103 Wiki Activity
OpenZFS on Linux and FreeBSD
5,239 Commits 42 Branches 132 Tags 226 MiB
C 70.3%
Shell 19.1%
Assembly 5.1%
M4 2.4%
Python 1.8%
Other 1.3%
Go to file
jdike 4c98586daf Fix lockdep recursive locking false positive in dbuf_destroy 
lockdep reports a possible recursive lock in dbuf_destroy.

It is true that dbuf_destroy is acquiring the dn_dbufs_mtx
on one dnode while holding it on another dnode.  However,
it is impossible for these to be the same dnode because,
among other things,dbuf_destroy checks MUTEX_HELD before
acquiring the mutex.

This fix defines a class NESTED_SINGLE == 1 and changes
that lock to call mutex_enter_nested with a subclass of
NESTED_SINGLE.

In order to make the userspace code compile,
include/sys/zfs_context.h now defines mutex_enter_nested and
NESTED_SINGLE.

This is the lockdep report:

[  122.950921] ============================================
[  122.950921] WARNING: possible recursive locking detected
[  122.950921] 4.19.29-4.19.0-debug-d69edad5368c1166 #1 Tainted: G           O
[  122.950921] --------------------------------------------
[  122.950921] dbu_evict/1457 is trying to acquire lock:
[  122.950921] 0000000083e9cbcf (&dn->dn_dbufs_mtx){+.+.}, at: dbuf_destroy+0x3c0/0xdb0 [zfs]
[  122.950921]
               but task is already holding lock:
[  122.950921] 0000000055523987 (&dn->dn_dbufs_mtx){+.+.}, at: dnode_evict_dbufs+0x90/0x740 [zfs]
[  122.950921]
               other info that might help us debug this:
[  122.950921]  Possible unsafe locking scenario:

[  122.950921]        CPU0
[  122.950921]        ----
[  122.950921]   lock(&dn->dn_dbufs_mtx);
[  122.950921]   lock(&dn->dn_dbufs_mtx);
[  122.950921]
                *** DEADLOCK ***

[  122.950921]  May be due to missing lock nesting notation

[  122.950921] 1 lock held by dbu_evict/1457:
[  122.950921]  #0: 0000000055523987 (&dn->dn_dbufs_mtx){+.+.}, at: dnode_evict_dbufs+0x90/0x740 [zfs]
[  122.950921]
               stack backtrace:
[  122.950921] CPU: 0 PID: 1457 Comm: dbu_evict Tainted: G           O      4.19.29-4.19.0-debug-d69edad5368c1166 #1
[  122.950921] Hardware name: Supermicro H8SSL-I2/H8SSL-I2, BIOS 080011  03/13/2009
[  122.950921] Call Trace:
[  122.950921]  dump_stack+0x91/0xeb
[  122.950921]  __lock_acquire+0x2ca7/0x4f10
[  122.950921]  lock_acquire+0x153/0x330
[  122.950921]  dbuf_destroy+0x3c0/0xdb0 [zfs]
[  122.950921]  dbuf_evict_one+0x1cc/0x3d0 [zfs]
[  122.950921]  dbuf_rele_and_unlock+0xb84/0xd60 [zfs]
[  122.950921]  dnode_evict_dbufs+0x3a6/0x740 [zfs]
[  122.950921]  dmu_objset_evict+0x7a/0x500 [zfs]
[  122.950921]  dsl_dataset_evict_async+0x70/0x480 [zfs]
[  122.950921]  taskq_thread+0x979/0x1480 [spl]
[  122.950921]  kthread+0x2e7/0x3e0
[  122.950921]  ret_from_fork+0x27/0x50

Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Jeff Dike <jdike@akamai.com>
Closes #8984
 		2019-09-25 11:27:49 -07:00
.github Update CONTRIBUTING to point users to IRC as well as mailing list 2019-03-13 11:57:57 -07:00
cmd systemd encryption key support 2019-09-25 11:27:49 -07:00
config Minor style cleanup 2019-09-25 11:27:49 -07:00
contrib Fix out-of-tree build failures 2019-09-25 11:27:48 -07:00
etc systemd encryption key support 2019-09-25 11:27:49 -07:00
include Fix lockdep recursive locking false positive in dbuf_destroy 2019-09-25 11:27:49 -07:00
lib Fix race in parallel mount's thread dispatching algorithm 2019-09-25 11:27:49 -07:00
man systemd encryption key support 2019-09-25 11:27:49 -07:00
module Fix lockdep recursive locking false positive in dbuf_destroy 2019-09-25 11:27:49 -07:00
rpm pkg-utils python sitelib for SLES15 2019-09-25 11:27:49 -07:00
scripts Fix out-of-tree build failures 2019-09-25 11:27:48 -07:00
tests Fix ZTS killed processes detection 2019-09-25 11:27:49 -07:00
udev Add enclosure_symlinks option to vdev_id 2018-12-14 17:27:49 -08:00
.gitignore git ignore python 3.7 virtual environment directories 2019-03-25 15:05:26 -07:00
.gitmodules Add zimport.sh compatibility test script 2014-02-21 12:10:31 -08:00
.travis.yml Add .travis.yml 2017-11-13 09:18:18 -08:00
AUTHORS Update build system and packaging 2018-05-29 16:00:33 -07:00
CODE_OF_CONDUCT.md Add CODE_OF_CONDUCT.md 2019-04-30 10:58:45 -07:00
COPYRIGHT Update build system and packaging 2018-05-29 16:00:33 -07:00
LICENSE Update build system and packaging 2018-05-29 16:00:33 -07:00
META Tag zfs-0.8.1 2019-06-14 09:43:18 -07:00
Makefile.am Fix out-of-tree build failures 2019-09-25 11:27:48 -07:00
NEWS Add NEWS file 2018-09-18 12:03:47 -07:00
NOTICE Update build system and packaging 2018-05-29 16:00:33 -07:00
README.md Explicitly state supported Linux versions 2018-05-30 20:11:19 -07:00
TEST Update build system and packaging 2018-05-29 16:00:33 -07:00
autogen.sh Cause autogen.sh to fail if autoreconf fails 2018-07-06 09:27:37 -07:00
configure.ac Fix out-of-tree build failures 2019-09-25 11:27:48 -07:00
copy-builtin Allow copy-builtin to work with modified sources 2018-10-17 12:06:05 -07:00
zfs.release.in Move zfs.release generation to configure step 2012-07-12 12:22:51 -07:00

README.md

img

ZFS on Linux is an advanced file system and volume manager which was originally developed for Solaris and is now maintained by the OpenZFS community.

codecov coverity

Official Resources

Installation

Full documentation for installing ZoL on your favorite Linux distribution can be found at our site.

Contribute & Develop

We have a separate document with contribution guidelines.

Release

ZFS on Linux is released under a CDDL license.
For more details see the NOTICE, LICENSE and COPYRIGHT files; UCRL-CODE-235197

Supported Kernels

  • The META file contains the officially recognized supported kernel versions.